net.sf.tweety.beliefdynamics.kernels

Class KernelContractionOperator<T extends Formula>

java.lang.Object

net.sf.tweety.beliefdynamics.MultipleBaseContractionOperator<T>

net.sf.tweety.beliefdynamics.kernels.KernelContractionOperator<T>

Type Parameters:

T - The type of formulas that this operator works on.

All Implemented Interfaces:

BaseContractionOperator<T>

Direct Known Subclasses:

RandomKernelContractionOperator

public class KernelContractionOperator<T extends Formula>
extends MultipleBaseContractionOperator<T>

This class implements kernel contraction for belief bases [Hansson:2001]. That is, contraction is realized by determining the set of kernel for the contraction, ie. the set of all minimal proofs for the formulas to be contracted, and then removing one formula from each kernel using an incision function.

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private EntailmentRelation<T>	entailmentRelation Used to determine kernels.
private IncisionFunction<T>	incisionFunction The incision function of the kernel contraction.

Constructor Summary

Constructors

Constructor and Description
KernelContractionOperator(IncisionFunction<T> incisionFunction, EntailmentRelation<T> entailmentRelation) Creates a new kernel contraction operator with the given incision function.

Method Summary

Modifier and Type	Method and Description
java.util.Collection<T>	contract(java.util.Collection<T> base, java.util.Collection<T> formulas) Contracts the first collection of formulas by the second collection of formulas.

Methods inherited from class net.sf.tweety.beliefdynamics.MultipleBaseContractionOperator

contract

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

incisionFunction

private IncisionFunction<T extends Formula> incisionFunction

The incision function of the kernel contraction.

entailmentRelation

private EntailmentRelation<T extends Formula> entailmentRelation

Used to determine kernels.

Constructor Detail

KernelContractionOperator

public KernelContractionOperator(IncisionFunction<T> incisionFunction,
                                 EntailmentRelation<T> entailmentRelation)

Creates a new kernel contraction operator with the given incision function.

Parameters:

incisionFunction - some incision function.

entailmentRelation - an entailment relation used to determine kernels.

Method Detail

contract

public java.util.Collection<T> contract(java.util.Collection<T> base,
                                        java.util.Collection<T> formulas)

Description copied from class: MultipleBaseContractionOperator

Contracts the first collection of formulas by the second collection of formulas.

Specified by:

contract in class MultipleBaseContractionOperator<T extends Formula>

Parameters:

base - some collection of formulas.

formulas - some formulas.

Returns:

the contracted collection.